Answer: by banning pages that share false news from purchasing advertisements.
On Aug. 28, Facebook announced its latest method in combatting false news, and it involves Facebook Pages and advertising.
If a Facebook Page repeatedly shares links to news articles that third-party fact-checking organizations determine to be false, the page will not be allowed to purchase advertising on the social network site. However, if the page owner stops sharing false news, they may be granted the ability to purchase ads once more.
"It is possible that someone could inadvertently share something, so we want to make sure that it is a repeated behavior," project manager at Facebook Rob Leathern told Mashable. “We want there to be an incentive: good maintenance. If they no longer are sharing [fake] stories, they can regain the ability. A repeated pattern of this occurring has a consequence."
This move is the latest in a series of efforts by the social media network to prevent the spread of false news through its channels.